L-Arginine erythrocyte transport in normal pregnant and preeclamptic women,

Objective Uptake of -arginine by the cell via amino acid transporter systems is the first step for nitric oxide (NO) production. The current study aimed to assess the total -arginine uptake in erythrocytes of normal pregnant and preeclamptic women. Study design Twenty-one normal pregnant and 21 preeclamptic women were studied. To measure total -arginine uptake in erythrocytes, carbon 14 was used as a marker and Michaelis-Menten kinetic parameters (Vmax and Km) were evaluated. Results In preeclamptic women, there was a significant increase (P<.004) in the mean maximal capacity of transport in erythrocytes (Vmax = 982.69 μmol/L cells/h±433.51) in comparison with normal pregnant women (Vmax = 584.73 μmol/L cells/h±422.33). No significant difference was detected in the half-saturation constant (P = 0.978). Conclusion The transport kinetics of the NO precursor, -arginine, is altered in erythrocytes of preeclamptic women. It is possible that abnormal -arginine uptake may contribute to the pathophysiologic mechanisms of preeclampsia syndrome